Yield monitor systems are used to measure crop yields during harvesting. Yield characteristics, such as weight or volume, are used to assess the quality and quantity of a crop and accordingly determine its purchase price. According to an example, a yield equation that assesses the quality and quantity of a crop is based on four distinct variables and a fifth related variable. In one example, the four variables include volume, temperature, moisture and test weight of the harvested crop. The fifth related variable is the weight of the harvested crop, and at least in some yield monitors the weight is determined according to the volume and test weight (e.g., a quantity similar to density).
According to one example, the test weight is input by the harvester operator based upon assumptions related to the harvested crop including observed field conditions, the crop being harvested, as well as the experience of the operator.